STM32MP157C-DK2 w/ Debian 9 does not see USB devices

Embedded Linux Discussions
21

5.10.59-armv7-lpae-x50

22

I came across this post while I was tyring to resolve the same / similar issue on a custom board using an STM32MP151 with Linux 5.1, uboot 2023.04. USB would appear to work briefly after power on, only once, then produce a voltage regulator error and boot cycle until power was physically removed.

[   31.844553] reg11: supplied by vdd
[   31.846632] reg18: supplied by vdd
[   31.849979] usb33: supplied by vdd_usb
[   31.853714] reg11: disabling
[   31.857421] reg18: disabling
[   31.859429] vdda: disabling

For me, the error was in not setting reg11, reg18, and usb33 regulators (defined here linux/stm32mp151.dtsi at v5.15-stm32mp · STMicroelectronics/linux (github.com) ) to regulator-always-on.

/*
 * Custom board .dtsi file
 */
&reg11 {
	regulator-always-on;
};

&reg18 {
	regulator-always-on;
};

&usb33 {
	regulator-always-on;
};